A221287 Equals two maps: number of n X n binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 n X n array.

1, 4, 92, 9107, 4983598, 10344276279

Offset: 1

Author

R. H. Hardin Jan 09 2013

Keywords

• nonn

Comments

Diagonal of A221290

Examples

			Some solutions for n=3
..0..0..0....0..0..1....0..1..0....0..0..0....0..0..1....0..1..1....0..0..1
..1..1..0....1..0..1....0..1..0....1..0..1....0..1..0....0..1..1....1..0..1
..1..1..0....1..1..0....1..1..0....1..0..0....1..1..0....0..1..0....1..0..0